farmers in a line weeding their rice paddy

Food supply wastes energy

Agriculture came about because it generated an energy surplus that allowed humans to do many other things than forage for food, but today agriculture is a huge energy sink.

What do you make of this graph from a fascinating book ‘The Future is Rural” by biologist and farmer Jason Bradford that tells the story of food production in the US in the currency of energy. 

Start on the right side of the graph with the food energy output per year as food consumed by the human population of the world, 1.1 Quads. 

Now compare that to the energy used to generate that food energy eaten—it takes 14.2 Quads to grow, store, deliver, sell and cook the food eaten.

Quads where a Quad is 1,000 trillion BTUs and one BTU is the heat required to raise the temperature of one pound of water by one degree Fahrenheit.

This ratio is not sustainable.

Recall that the logic of the invention of agriculture 12,000 years ago was that it generated an energy surplus that was enough to get people through lean times and seasonal shortages of game and forage. The energy surplus allowed people to stay put with a division of labour and create complex societies. 

Modern food supply systems are the opposite. They are colossal energy sinks.

Here is how Jason Bradford summarised the numbers in the graph.

The modern food system runs a large energy deficit and so do most farms. Our energy-sink food system is an aberration that will eventually appear as a blip in human history, and we will require our farms to run an energy surplus to avoid starvation.

Jason Bradford 

Why is it a blip? 

Because the energy sunk into the production, processing, packaging, distribution, and waste of food comes from fossil fuels—an army of energy slaves that we dig up and pump out of the ground for the tiny cost of extraction. And that energy source is about to run out in the case of oil. Coal and gas we should not burn or risk massive climate shifts.

We are lounging in a gluttonous age of cheap energy and cheap food unprecedented in human history and converting the gift into people. 

This is neither good nor bad; it is just ecology.

Give any organism excess resources with no controls, and the population will expand at the maximum reproductive rate.

Humans use fossil fuel energy to create a food excess that becomes more humans. This is what nature does with an energy source. It uses the power to defy entropy and make more. Humans are different because our technology is exceptional at creating opportunities.

But we do something else that is different.

What the market tells us

Nobody can do business at a loss, so the push for profit encourages efficiency. This is indeed the claim of industrial agriculture and the supply chain that maintains it—big fields sown with monoculture crops 

If this claim is valid, how can the food supply system use 13x more energy than gets eaten?

We are told that the market is efficient but the food supply systems only function because of the cheap energy from fossil fuels.

In other words, the profits that accrue to the businesses in the supply chain—and they do make a profit; otherwise, they would not be in business—are subsidised by ancient energy—the hard work of plants and animals millions of years ago.

Businesses are efficient from a profit perspective rather than from collective energy use.

Nature is energy efficient, modern humans are not.

Don’t blame the farmers

Food production, the base of the supply chain that comes from the efforts of farmers, uses just shy of 2 Quads for the 1.1 Quads eaten.

Not great net efficiency but is out of the park compared to the 12.2 Quads needed to make the food energy available to the household or the 0.7 Quads of food waste at the table.

Tempting as it is to blame the farmers, they are not the problem. Soon they will revert back to less energy-intensive forms of production as the costs of inputs rises. Recall that before tractors, farming generated an energy surplus.

The real problem and the opportunity for huge energy savings is consumer behaviour. It is about what we choose to eat, how we prepare our food and what we manage to waste.

One of the reasons we put diet in the trifecta.

Photo by Rob Mulder on Unsplash

What sustainably FED suggests

Mechanization and globally traded commodities have steadily replaced human and animal labour and local markets in the industrial food system. Every step in the industrial food system requires energy and lots of it—a person eating a meal in the United States is consuming only one kilocalorie of food for every 10 kilocalories spent getting that food to their plate.

It may be that a new energy source emerges that doesn’t pollute the planet. There is already a rush on renewables that need more resources than the planet can cough up just to build and maintain and the technofix may lull some people to sleep.

Clean energy would be huge. Sustainable clean energy would be magnificent.

We don’t have either, not at scale. 

In the interim, we suggest tackling the supply chain. Rather than focusing on inefficiency and energy conservation, how about going at it through diet?

Science source

Bradford, J., 2019. The Future is Rural: Food System Adaptations to the Great Simplification.

Hero image from photo by Nuril Fikriyah on Unsplash


Mark is an ecology nerd who was cursed with an entrepreneurial gene and a big picture view making him a rare beast, uncomfortable in the ivory towers and the disconnected silos of the public service. Despite this he has made it through a 40+ year career as a scientist and for some unknown reason still likes to read scientific papers.

Add comment

Subscribe to our explainer series

* indicates required

Most discussed